Permission for read, write, and execute may be defined for the user-owner, for the group-owner, and for the world (any users who
are not the owner of, or in the same group as, the object). Thus there are nine individual permissions (rwxrwxrwx) per object.

All users are members of at least one group, possibly more.

A new filesystem object inherits the user ownership of its creator, and the group ownership of its
parent directory. Consequently, all objects have a user-owner, a group-owner, and a set of permissions.

The user-owner of an object can interact with that object based on the file permissions for the user-owner (eg. rwx------).

Any user who is a member of the same group as a particular filesystem object (ie. a group-owner) can interact with
that object based on the file permissions for the group-owner (eg. ---rwx---).

Any user who is not the owner of, AND is not in the same group as, a particular filesystem object (ie. neither
user-owner or group-owner) can interact with that object based on the file permissions for the world (eg. ------rwx).

File permissions (eg. rwxrwxrwx) may be represented numerically (eg. 777). These are equivalent and interchangable.
The conversion is done by assigning a value to r (4), w (2) and x (1), then adding them together. This is done for
the owner, for the group, and for the world, then these numbers are placed in a single string. Example: